Steering mechanism

Abstract

To provide a rack and pinion type steering mechanism capable of making a distance between right and left wheels of a vehicle shorter than the length of a rack and pinion.SOLUTION: A steering mechanism 1 includes a rack and pinion 94 having a pinion gear connected to an intermediate shaft 93 rotated with steering of a vehicle, and a rack gear engaged with the pinion gear and moved in the lateral direction with rotation of the pinion gear. The rack and pinion 94 is disposed outside a space S formed between a right wheel 8R and a left wheel 8L. The steering mechanism 1 transmits a force in the left-right direction applied to the rack gear of the rack and pinion 94 to a steering knuckle 8R attached to the wheel 95R and a steering knuckle 8L attached to the wheel 95L via the power transmission member 11.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a rack-and-pinion type vehicle steering mechanism. [Background technology]

[0002] A commonly used steering mechanism for vehicles is the rack-and-pinion type, which has a pinion gear connected to a shaft that rotates when steering, and a rack gear that meshes with the pinion gear and moves as the pinion gear rotates.

[0003] In a rack-and-pinion steering mechanism, the right end of the right tie rod extending to the right from the rack gear is connected to the steering knuckle attached to the vehicle's right wheel, and the left end of the left tie rod extending to the left from the rack gear is connected to the steering knuckle attached to the vehicle's left wheel.The rack gear, which moves left and right as steering is performed, pushes and pulls the left and right steering knuckles via the left and right tie rods, thereby changing the angle of the rotational axis of the right and left wheels relative to the fore-and-aft direction of the vehicle body.

[0004] Patent document 1, for example, discloses a rack-and-pinion steering mechanism. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-1478 Summary of the Invention [Problem to be solved by the invention]

[0006] When using a conventional rack-and-pinion steering mechanism, the distance between the left and right wheels of the vehicle cannot be made shorter than the length of the rack-and-pinion, which is an assembly part that includes the pinion gear and rack gear mentioned above.

[0007] The present invention provides a rack-and-pinion steering mechanism that enables the distance between the left and right wheels of a vehicle to be shorter than the length of the rack and pinion, and a vehicle equipped with a rack-and-pinion steering mechanism in which the distance between the left and right wheels of the vehicle is shorter than the length of the rack and pinion. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the present invention provides a steering mechanism including: a pinion gear connected to a shaft that rotates as the vehicle is steered; a rack gear that meshes with the pinion gear and moves as the pinion gear rotates, and that is positioned outside the space formed between the right and left wheels of the vehicle when the rotation axes of the right and left wheels are perpendicular to the fore-and-aft direction of the vehicle body; and a power transmission member connected to the rack gear, a steering knuckle attached to the right wheel of the vehicle, and a steering knuckle attached to the left wheel of the vehicle, and a vehicle equipped with the steering mechanism. [Effects of the Invention]

[0009] According to the present invention, a vehicle is provided with a rack-and-pinion steering mechanism, and the distance between the left and right wheels of the vehicle is shorter than the length of the rack-and-pinion. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram showing the configuration of a steering mechanism according to an embodiment. [Figure 2] FIG. 10 is a diagram showing the configuration of a steering mechanism according to a modified example. [Figure 3]FIG. 10 is a diagram showing the configuration of a steering mechanism according to a modified example. [Figure 4] FIG. 1 is a diagram showing the configuration of a steering mechanism according to a conventional technique. [Figure 5] FIG. 1 is a diagram showing the configuration of a rack and pinion according to the prior art. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Prior art] Figure 4 shows the configuration of a rack-and-pinion steering mechanism 9 of a vehicle according to the prior art. Figure 4(A) shows the vehicle with the steering wheel 91 turned neither left nor right, and Figure 4(B) shows the vehicle with the steering wheel 91 turned to the right (rotated clockwise).

[0012] In this application, left and right refer to left and right as seen from the driver of the vehicle, and clockwise and counterclockwise refer to clockwise and counterclockwise as seen from the driver of the vehicle. In addition, in this application, up and down refer to up and down when the vehicle is placed on the ground in a state where it can run, and front and rear refer to front and rear as seen from the driver when the vehicle is moving straight on the ground.

[0013] The steering mechanism 9 comprises the following components: Steering wheel 91: The part that the driver operates to steer. Steering column 92: A part that holds the axis of the steering wheel 91 rotatably. Intermediate shaft 93: A shaft connecting the steering column 92 and the rack and pinion 94 (an example of a shaft that rotates when the vehicle is steered). Rack and pinion 94: A component that converts the rotational force applied to the steering wheel 91 by the driver's steering into left and right forces on the left and right wheels. Steering knuckle 95R: A part that is attached to the vehicle body 7 so as to be freely rotatable around a vertical rotation axis AR, connects the rack and pinion 94 to the right wheel 8R (an example of a right wheel), and converts the force applied in the left-right direction from the rack and pinion 94 into a rotational force around the rotation axis AR and transmits it to the wheel 8R. Steering knuckle 95L: A part that is attached to the vehicle body 7 so as to be freely rotatable around a vertical rotation axis AL, connects the rack and pinion 94 to the left wheel 8L (an example of a left wheel), and converts the force applied in the left-right direction from the rack and pinion 94 into a rotational force around the rotation axis AL and transmits it to the wheel 8L.

[0014] 5 is a diagram showing the configuration of the rack and pinion 94. The rack and pinion 94 includes the following components: Pinion shaft 941: A shaft connected to the intermediate shaft 93. Pinion gear 942: A pinion gear that is connected to the intermediate shaft 93 via the pinion shaft 941 and rotates as the intermediate shaft 93 rotates. Rack gear 943: A rack gear that meshes with the pinion gear 942 and moves left and right as the pinion gear 942 rotates. Tie rod 944R: A rod extending rightward from the right end of the rack gear 943. Tie rod 944L: A rod extending leftward from the left end of the rack gear 943. Ball joint 945R: A part provided at the right end of the tie rod 944R, which rotatably connects the tie rod 944R and the steering knuckle 95R. Ball joint 945L: A part provided at the left end of the tie rod 944L, which rotatably connects the tie rod 944L and the steering knuckle 95L. Gearbox 946: A box that accommodates a part of the pinion shaft 941, the pinion gear 942, the rack gear 943, a part of the tie rod 944R, and a part of the tie rod 944L.

[0015] With the steering mechanism 9 having the above configuration, when the driver rotates the steering wheel 91 clockwise, the pinion gear 942 rotates clockwise, the rack gear 943 moves leftward, the tie rod 944R pulls the steering knuckle 95R leftward, and the tie rod 944L pushes the steering knuckle 95L leftward, causing the wheels 8R and 8L to rotate clockwise relative to the front-to-rear direction of the vehicle as viewed from above, resulting in the state shown in FIG. 4(B). When the wheels 8R and 8L roll forward in this state, the vehicle turns right as it travels. When the driver rotates the steering wheel 91 counterclockwise, the steering mechanism 9 behaves in a manner that reverses the left-right behavior described above, resulting in the vehicle turning left as it travels.

[0016] [Embodiment] Fig. 1 is a diagram showing the configuration of a steering mechanism 1 according to one embodiment of the present invention. In the following description, among the components of the steering mechanism 1, those that are common to the components of the steering mechanism 9 will be denoted by the same reference numerals as those used in the steering mechanism 9. For example, the steering wheel 91 of the steering mechanism 1 shown in Fig. 1 is the same component as the steering wheel 91 of the steering mechanism 9 shown in Fig. 4.

[0017] FIG. 1(A) shows a vehicle with the steering wheel 91 not turned to the left or right, and FIG. 1(B) shows a vehicle with the steering wheel 91 turned to the right (rotated clockwise).

[0018] Below, differences between the steering mechanism 1 and the steering mechanism 9 will be mainly described, and descriptions of commonalities between the steering mechanism 1 and the steering mechanism 9 will be omitted as appropriate.

[0019] The steering mechanism 1 includes the following components in addition to the components common to the steering mechanism 9. Power transmission member 11: A part having a wide portion 111 connected to the tie rod 944R and tie rod 944L of the rack and pinion 94, and a narrow portion 112 extending from the left-right center of the wide portion 111 toward the space S between the wheels 8R and 8L, and having a left-right length (width) narrower than that of the wide portion 111. Tie rod 12R: A rod extending rightward from the narrow portion 112 of the power transmission member 11. Tie rod 12L: A rod extending leftward from the narrow portion 112 of the power transmission member 11. Ball joint 13R: A component provided at the right end of the tie rod 12R, which rotatably connects the tie rod 12R and the steering knuckle 95R. Ball joint 13L: A part provided at the left end of the tie rod 12L that rotatably connects the tie rod 12L and the steering knuckle 95L.

[0020] It should be noted that the rack and pinion 94 provided in the steering mechanism 1 does not necessarily need to be rotatably connected to the wide portion 111 of the power transmission member 11. Therefore, instead of the steering mechanism 1 being connected to the wide portion 111 of the power transmission member 11 by ball joints 945R and 945L as shown in Fig. 1, the rack and pinion 94 may not be provided with ball joints 945R and 945L, and tie rods 944R and 944L may be directly connected to the wide portion 111 of the power transmission member 11.

[0021] The rack gear 943 of the rack and pinion 94 provided in the steering mechanism 1 is disposed outside the space S.

[0022] The space S is the space formed between the wheels 8R and 8L when the rotation axes of the wheels 8R and 8L are perpendicular to the front-rear direction of the main body 7, that is, in the state shown in FIG. 1(A).

[0023] The power transmission member 11 is connected to the rack gear 943 via tie rod 944R and tie rod 944L, connected to the steering knuckle 95R via tie rod 12R and ball joint 13R, and connected to the steering knuckle 95L via tie rod 12L and ball joint 13L.

[0024] As described above, the power transmission member 11 connected to each of the rack gear 943, the steering knuckle 95R, and the steering knuckle 95L plays a role in transmitting the lateral force that the rack gear 943 of the rack and pinion 94, which is located outside the space S, receives in response to steering by the driver, to the steering knuckle 95R and the steering knuckle 95L, which are located within the space S.

[0025] According to the steering mechanism 1 having the above configuration, a vehicle can be realized in which the distance between the wheels 8R and 8L when the steering wheel 91 is not turned to either the left or right is shorter than the length of the rack and pinion 94.

[0026] [Variations] The above-described embodiment is a specific example of the present invention, and various modifications are possible within the scope of the technical concept of the present invention. Examples of such modifications are shown below. Note that two or more of the following modifications may be combined as appropriate.

[0027] (1) In the steering mechanism 1, the lateral force applied to the rack gear 943 by steering is transmitted to the steering knuckles 95R and 95L via the power transmission member 11. At this time, if the power transmission member 11 moves in the up-down or front-back direction, part of the lateral force applied to the rack gear 943 by steering escapes in the up-down or front-back direction, and part of the steering force is not transmitted to the steering knuckles 95R and 95L, which may result in poor steering response.

[0028] In order to reduce the above problem, a configuration may be adopted in which the power transmission member 11 is connected to the vehicle body 7 so as to be slidable in a direction parallel to the direction of movement of the rack gear 943.

[0029] Figure 2 shows the configuration of a steering mechanism 1 according to one example of this modification. Figure 2(A) shows a vehicle with the steering wheel 91 not turned to the left or right, and Figure 2(B) shows a vehicle with the steering wheel 91 turned to the right (rotated clockwise).

[0030] The power transmission member 11 of the steering mechanism 1 shown in Fig. 2 includes an inner rail 113. The vehicle body 7 shown in Fig. 2 also includes an outer rail 71 that sandwiches the inner rail 113 and holds the inner rail 113 slidably. When a lateral force is applied to the power transmission member 11 from the rack gear 943 during steering, the inner rail 113 and the outer rail 71 do not restrict the lateral movement of the power transmission member 11, but restrict the vertical and longitudinal movement of the power transmission member 11. As a result, steering response is not impaired.

[0031] The combination of inner rail 113 and outer rail 71 is one example of a mechanism (sliding mechanism) that slidably connects power transmission member 11 to main body 7 in a direction parallel to the moving direction of rack gear 943, and various other sliding mechanisms can be adopted instead of the combination of inner rail 113 and outer rail 71. For example, main body 7 may include an inner rail, and power transmission member 11 may include an outer rail that slidably holds the inner rail of main body 7. Furthermore, main body 7 and power transmission member 11 may be connected by two or more sets of sliding mechanisms.

[0032] (2) In the above embodiment, the power transmission member 11 and the tie rod 12R and tie rod 12L are separate members, but they may be configured as a single member.

[0033] (3) The shapes, sizes, arrangements, etc. of the components constituting the steering mechanism 1 shown in FIG. 1 are merely examples and may be modified in various ways.

[0034] For example, in the above-described embodiment, the power transmission member 11 is disposed in a position in which its normal direction (direction perpendicular to the flat surface) is the up-down direction, but the position of the power transmission member 11 is not limited to this.

[0035] FIG. 3 is a diagram showing the configuration of a steering mechanism 1 according to one example of this modified example (viewed from the right side).

[0036] The vehicle body 7 in Figure 3 comprises a main frame 70 extending in the Y direction, and a base 72 which is a plate-shaped member that stands up from the main frame 70 in the Z direction and whose normal direction is the fore-and-aft direction, and an outer rail 71 is arranged on the side of the base 72 on the -Y direction side.

[0037] The power transmission member 11 provided in the steering mechanism 1 of the vehicle in Figure 3 is positioned in an attitude in which its normal direction is the front-to-rear direction, and an inner rail 113 is positioned on the side surface of the power transmission member 11 in the +Y direction.

[0038] In the steering mechanism 1 shown in FIG. 3, when the rack gear 943 of the rack and pinion 94 receives a force in the X direction as the driver turns the steering wheel, the force is transmitted to the steering knuckles 95R and 95L via the power transmission member 11.

[0039] (4) The present invention provides a steering mechanism exemplified by the steering mechanism 1, as well as a vehicle equipped with the steering mechanism. [Explanation of symbols]

[0040] 1...steering mechanism, 7...main body, 8...wheel, 9...steering mechanism, 11...power transmission member, 12...tie rod, 13...ball joint, 70...main frame, 71...outer rail, 72...base, 91...steering wheel, 92...steering column, 93...intermediate shaft, 94...rack and pinion, 95...steering knuckle, 111...wide portion, 112...narrow portion, 113...inner rail, 941...pinion shaft, 942...pinion gear, 943...rack gear, 944...tie rod, 945...ball joint, 946...gearbox.

Claims

1. a pinion gear connected to a shaft that rotates in response to steering of the vehicle; a rack gear that meshes with the pinion gear, moves in accordance with the rotation of the pinion gear, and is disposed outside a space formed between the right wheel and the left wheel when the rotation axes of the right wheel and the left wheel of the vehicle are perpendicular to the front-rear direction of the vehicle body; a power transmission member connected to the rack gear, a steering knuckle attached to a right wheel of the vehicle, and a steering knuckle attached to a left wheel of the vehicle; A steering mechanism comprising:

2. The power transmission member is connected to the vehicle body so as to be slidable in a direction parallel to the direction of movement of the rack gear.

2. A steering mechanism according to claim 1.

3. A vehicle comprising the steering mechanism according to claim 1 or 2.

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